Magnetic resonance relaxometry, conducted by field cycling, has become an increasingly popular technique in recent years. In particular, it has the ability to monitor biomass transformation which is of particular interest to wastewater treatment. Traditional field cycling often uses expensive and large electromagnets. In this work we present a small, portable field cycling sensor which can detect changes in biomass in constructed wetland samples.
Fast field cycling is a technique that uses a varying magnetic field applied to a sample, polarising it at a high field, allowing it time to develop at a lower field and then collecting the data at the same initial high field. This change in T1 can reveal interesting properties of the samples not achievable by traditional methods.
A desktop magnetic resonance sensor that undertakes relaxometry measurements using field cycling has been developed using a combination of permanent magnets and electrical coils which has been used to test a range of samples. We demonstrate the effectiveness of this sensor by conducting measurements of T1 at different field strengths for wetland samples at different stages of biofilm growth.